The invention relates to the use of dry building materials for the surface treatment of cementitious substrates, a process for the surface treatment of cementitious substrates and also the surface-treated cementitious substrates which can be obtained in this way.
Cementitious substrates can be obtained by coating substrates with aqueous compositions based on cement, fillers and optionally additives. Cementitious substrates are open-pored and require an after-treatment, for example sealing or coating with a nonporous layer, in order to improve their mechanical properties and to reduce their soiling tendency. DE-A 2111362 recommends coating of cured concrete with self-hardening, liquid coating compositions based on polymerizable organic compounds, hardeners and optionally further organic polymers for this purpose. JP 59051967 recommends the use of paste-like, aqueous compositions containing organic polymers and hydraulically setting binders for sealing walls. Processes for producing industrial floors, in which a concrete screed is coated with a paste-like coating composition composed of stoneware, a curable, epoxide-containing synthetic resin, a hardener and a fluidizing binder and a coating is obtained by curing, are known from DE-A 60100076. Finally, WO-A 2006/095346 describes the coating of surfaces with decorative protective layers based on polymer resins, colored particles and glass particles.
In the light of this background, it was an object of the invention to provide efficient measures for the surface treatment of cementitious substrates, which should lead to an improvement in the mechanical properties, in particular the abrasion resistance, and a reduction in the soiling tendency of the cementitious substrates, and in which no voluminous layer should be applied to the cementitious substrates if possible.